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The time evolution of cosmological parameters in early Universe at the deconfinement transition is studied by an equation of state (EoS) which takes into account the finite baryon density and the background magnetic field. The non…

High Energy Physics - Phenomenology · Physics 2015-09-30 Paolo Castorina , Vincenzo Greco , Salvatore Plumari

We study the BCS gap equation for a Fermi gas with unequal population of spin-up and spin-down states. For $\cosh(\delta_\mu/T) \leq 2$, with $T$ the temperature and $\delta_\mu$ the chemical potential difference, the question of existence…

Mathematical Physics · Physics 2015-05-28 Abraham Freiji , Christian Hainzl , Robert Seiringer

The recent experimental realization of spin-orbit coupling for ultra-cold atoms has generated much interest in the physics of spin-orbit coupled degenerate Fermi gases. Although recently the BCS-BEC crossover in three-dimensional (3D)…

Quantum Gases · Physics 2012-01-05 Gang Chen , Ming Gong , Chuanwei Zhang

We review the BCS to Bose Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction $\Psi_0$. While this ground state has been summarized extensively in the…

Superconductivity · Physics 2011-09-13 Qijin Chen , Jelena Stajic , Shina Tan , Kathryn Levin

The superfluidity and pairing phenomena in ultracold atomic Fermi gases have been of great interest in recent years, with multiple tunable parameters. Here we study the BCS-BEC crossover behavior of balanced two-component Fermi gases in a…

Quantum Gases · Physics 2020-05-20 Jibiao Wang , Leifeng Zhang , Yi Yu , Chaohong Lee , Qijin Chen

We investigate the crossover from the Bardeen-Cooper-Schrieffer (BCS) state of weakly-bound Cooper pairs to the Bose-Einstein Condensate (BEC) of strongly-bound molecular dimers in a gas of ultracold atoms loaded on a two-dimensional…

Quantum Gases · Physics 2012-08-21 Luca Salasnich , Flavio Toigo

We present a mean field approach based on pairs of fermionic atoms to describe condensates in the BEC-BCS crossover regime. By introducing an effective potential, the mean field equation allows us to calculate the chemical potential, the…

Superconductivity · Physics 2007-05-23 Cheng Chin

Ultracold atom gases provide model systems in which many-body quantum physics phenomena can be studied. Recent experiments on Fermi gases have realized a phase transition to a Fermi superfluid state with strong interparticle interactions.…

Other Condensed Matter · Physics 2008-09-04 J. T. Stewart , J. P. Gaebler , D. S. Jin

The crossover from weak coupling Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) of tightly bound pairs, as a function of the attractive interaction in Fermi systems, has long been of interest to theoretical…

Quantum Gases · Physics 2014-04-09 Mohit Randeria , Edward Taylor

We show that in an atomic Fermi gas near a Feshbach resonance the crossover between a Bose-Einstein condensate of diatomic molecules and a Bose-Einstein condensate of Cooper pairs occurs at positive detuning, i.e., when the molecular energy…

Statistical Mechanics · Physics 2011-08-12 G. M. Falco , H. T. C. Stoof

The physics of atomic quantum gases is currently taking advantage of a powerful tool, the possibility to fully adjust the interaction strength between atoms using a magnetically controlled Feshbach resonance. For fermions with two internal…

Quantum Gases · Physics 2015-05-27 Yvan Castin , Félix Werner

We report the experimental measurement of the equation of state of a two-dimensional Fermi gas with attractive s-wave interactions throughout the crossover from a weakly coupled Fermi gas to a Bose gas of tightly bound dimers as the…

Quantum Gases · Physics 2016-02-02 I. Boettcher , L. Bayha , D. Kedar , P. A. Murthy , M. Neidig , M. G. Ries , A. N. Wenz , G. Zürn , S. Jochim , T. Enss

We discuss the superfluid phase transition of a strongly interacting Fermi gas with unequal (asymmetric) chemical potentials in two pairing hyperfine states, and map out its phase diagram near the BCS-BEC crossover. Our approach includes…

Statistical Mechanics · Physics 2007-05-23 Xia-Ji Liu , Hui Hu

We demonstrate atom-resolved detection of itinerant bosonic $^{23}$Na and fermionic $^6$Li quantum gases, enabling the direct in situ measurement of interparticle correlations. In contrast to prior work on lattice-trapped gases, here we…

Quantum Gases · Physics 2025-11-25 Ruixiao Yao , Sungjae Chi , Mingxuan Wang , Richard J. Fletcher , Martin Zwierlein

We develop a functional integral formalism for ultracold gases of fermionic atoms. It describes the BEC - BCS crossover and involves both atom and molecule fields. Beyond mean field theory we include the fluctuations of the molecule field…

Superconductivity · Physics 2010-10-27 S. Diehl , C. Wetterich

We develop a self-consistent theory unifying the description of a quantum Fermi gas in the presence of a Fano-Feshbach resonance in the whole phase diagram ranging from BCS to BEC type of superfluidity and from narrow to broad resonances,…

Quantum Gases · Physics 2019-08-29 Pietro Maria Bonetti , Maria Luisa Chiofalo

We theoretically investigate the uniform spin susceptibility $\chi$ in the superfluid phase of an ultracold Fermi gas in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. In our previous paper [H.…

Quantum Gases · Physics 2016-01-20 H. Tajima , R. Hanai , Y. Ohashi

Boson-fermion mixture exist in nature as quark-gluon plasma and $^3$He-$^4$He mixture. We proposed a convective boson-fermion pairing theory, that can be implemented by ultracold atoms in optical superlattice transformation between…

Strongly Correlated Electrons · Physics 2020-07-09 Tieyan Si

Confined ultracold atoms in optical lattices provide a versatile platform for simulating lattice models of strongly correlated quantum systems, where pairing phenomena and superfluid phases can be explored under controlled conditions. While…

Quantum Gases · Physics 2026-05-13 G. Diniz , I. M. Carvalho , M. Sanino , F. Iemini , V. V. França

The spectrum of two spin-up and two spin-down fermions in a trap is calculated using a correlated gaussian basis throughout the range of the BCS-BEC crossover. These accurate calculations provide a few-body solution to the crossover…

Superconductivity · Physics 2009-11-13 Javier von Stecher , Chris H. Greene